Figure 1. Shear stress elicits longitudinal Ca²⁺ waves by triggering IP₃Rs and subsequent CICR through the RyRs .

A and D, confocal Ca²⁺ images recorded during the application of shear stress (∼16 dyn cm⁻²) in the control solutions (‘Con, shear’) and in the presence of 1 mm tetracaine (10 s; A, ‘Tetra, shear’) or 2 μm 2‐APB (D, ‘2‐APB, shear’) in the representative rat atrial myocytes. Arrows indicate Ca²⁺ wave core. B and E, changes in Ca²⁺ fluorescence were measured (at 60 Hz) from the region‐of‐interest (ROI) with corresponding colours (inset) using the Ca²⁺ images recorded in the cells illustrated in A (B) and D (E). The time marked by arrowheads matches with 0 ms shown in the confocal images. Local Ca²⁺ signals (green and violet) represent Ca²⁺ movement during the longitudinal Ca²⁺ wave. Whole‐cell Ca²⁺ change during the wave is shown as a black trace. C and F, summary of the number of longitudinal (L‐) waves and whole‐cell Ca²⁺ increases during 8‐s application of shear stress in the absence (‘Con’) and presence of 1 mm tetracaine (‘Tetra’; n = 9; C) or 2 μm 2‐APB (n = 14; F). ***P < 0.001 vs. ‘Con’ (paired Student's t test).